A method like this, or alternatively, a corresponding device, is known from EP 0084391. Within this context, a radiation source, such as a hollow cathode lamp or a discharge lamp without electrodes, generates monochromatic radiation, which is separated by a beam separator into a test (sample) beam and a reference beam. The test beam is led through a test area in which a sample is atomized by means of a flame. The atomized sample absorbs part of the radiation, and the quantity of radiation absorbed represents a qualitative measure (unit of measurement) for the concentration of the element in the sample that is to be analyzed. Following the test area, the test beam is transferred through a series of optical elements and reunited the radiation is created. After leaving the monochromator, the spectrally dissected radiation hits a detector system.
Other atom absorption spectrometers are known, which reunite a test beam and a reference beam through a chopper, while the beams' intensities are determined in correspondence to the chopper's frequency.
Another known system consists of atom absorption spectrometer containing movable mirrors, which either allow a single beam to pass through the test area or deflect it in order to circumvent it. The reference beams' intensities are therefore measured between the test beams' intensities, with the measuring frequency based on the mirror's movement. It has to be noted, though, that any change in the mirrors' position results in a direct change of the beams' intensity and therefore leads to a shift in the base lines.
Finally, it is also known to periodically remove the test area, or, alternatively, the burner mounted in it, including the accompanying flame, from the orbit of the test beam. With this, however, frequency is comparatively low and demands an exact control of the burner's movement to avoid changes in sensitivity. Additionally, the measurements of the reference's intensity in the test area might be affected by the operator's activities.